[Comparison of lidocaine and urapidil for prevention of hemodynamic response to tracheal intubation in patients in general good health].

OBJECTIVE: To compare the efficacy of endovenous administration of 0.5 mg/kg-1 of urapidil to 1 mg/kg-1 of lidocaine for attenuating hemodynamic response to laryngoscopy and tracheal intubation.

PATIENTS AND METHODS: Study of 40 ASA I and II patients with normal blood pressure undergoing elective surgery under general anesthesia with orotracheal intubation. The patients were randomly assigned to two groups to receive either 0.5 mg/kg-1 of urapidil or 1 mg/kg-1 five minutes before anesthetic induction. Anesthesia was provided with 0.04 mg/kg-1 of midazolam, 2 micrograms/kg-1 of fentanyl, 2 mg/kg-1 of propofol, 0.1 mg/kg-1 of vecuronium before proceeding to orotracheal intubation, after electromyographic determination of neuromuscular response with T1 less than 5%, and laryngoscopy. Heart rate, systolic, diastolic and mean pressures, and the product of heart rate and mean arterial pressure (HR x MAP) were recorded at the following times: baseline (before administering either lidocaine or urapidil), after induction, after laryngoscopy and intubation, and 3 minutes and 5 minutes after intubation.

RESULTS: ASA classification, age, sex and weight were similar in the two groups. Heart rate immediately after intubation, and after 3 and 5 minutes was significantly lower in the lidocaine group. Likewise HR x MAP immediately after intubation and 3 minutes later was significantly lower in the patients who received lidocaine.

CONCLUSIONS: In healthy ASA I and II patients with normal blood pressure, a dose of 1 mg/kg-1 of lidocaine provided better protection against the hemodynamic response to laryngoscopy and tracheal intubation than does 0.5 mg/kg-1 of urapidil.